1. Field of the Invention
The present invention relates to a skate for jumping. More particularly, the invention relates to improved in-line roller skates, improved ice skates, and improved conventional roller skates, which provide effective energy storage/release to enable a relatively high jump, controlled landing, and reduced impact.
2. Description of the Related Art
Spring-assisted skates are disclosed in the patent art. Most of these prior arts use small springs and claim shock absorbing characteristics. only a couple of prior arts claim jump-assisting characteristics. Such skates are disclosed in U.S. Pat. No. 1,597,792 issued to E. A. Hoff et al (1926); U.S. Pat. No. 4,351,538 issued to Berta (1982); and U.S. Pat. No. 5,503,413 issued to Belogour (1996). These prior arts include an ice skate, a conventional roller skate, and an in-line roller skate. Each of the skates comprises components including a boot, a surface-engaging blade or roller assembly (hereinafter referred to as the surface engager), and a means using spring(s) for shock absorbing or jump assistance.
In general, these prior spring-assisted skates have the following disadvantages:
(a) No effective rotational control of the surface engager from the boot. In particular, the surface engager is allowed to rotate with respect to the boot, thus a skater cannot select a specific part of the surface engager to initiate a jump or support a landing. In other words, a skater""s jump is limited to certain ways, and the landing becomes more difficult because of the uncertain orientation of the surface engager.
(b) No significant storage/release of energy to assist a jump because only small spring deformation is practical for these prior arts. Based on their design configurations, prior arts may further lose control of surface engagers and skate structural integrity if relatively large spring deformation is adopted.
Other spring-assisted prior arts related to self-propelling skates are disclosed in U.S. Pat. No. 4,451,055 issued to Robert E. Lee (1984) and U.S. Pat. No. 2,174,990 issued to F. R. Maguire (1939). These arts fall into the following disadvantages:
(a) Lack of jump assistance: These prior arts utilize the energy from the weight force entirely for forward propulsion, not jump assistance. A spring means may be used to bias the boot from the surface engager only when a skate (or weight carrier) is manually raised off the ground. Because a strong spring will create strong resistance and defeat the main purpose of propelling, only soft springs may or may not be used, which is apparently incapable of jump assistance.
(b) Hazardous for landing: These prior arts are not intended for jumping, and will definitely be hazardous in landing. Upon landing, these skates will propel and accelerate forward as the arts intend, thus making it virtually impossible for a skater to maintain balance.
Accordingly, objects and unique advantages of the present invention are:
1. to provide a spring-assisted skate with large spring deformation for effective jump assistance;
2. to provide a spring-assisted skate with zero rotation between the surface engager and the boot for effective jump/landing control;
3. to provide a spring-assisted skate with structural integrity during large deformation.
These and other objects of the invention are realized by interposing a link/spring mechanism between the boot and the surface engager.
A link/spring mechanism comprises at least two links and at least one spring (coil or wound). The links and spring(s) are made of metallic (such as aluminum alloy), synthetic (such as plastics), or composite materials (such as graphite/epoxy).
The link/spring mechanism is connected to the boot and the surface engager with pin (also made of metallic, synthetic, or composite materials) joints in such a way that
i. the spring(s) deforms with relative displacements between the boot and the surface engager;
ii. the boot base is maintained parallel to the surface engager throughout the entire range of skate deformation.
Thus a skater can force the boot down towards the surface engager to store energy and then jump to release the energy for increased height. Being certain that the surface engager is parallel to the boot base, the skater can land with as much control as if wearing a regular skate even more comfortably due to the effective shock-absorbing characteristics of the jump skate.
Other objects, features and advantages of the invention shall become apparent from the following detailed description of the preferred embodiments thereof, when considered in conjunction with the drawings wherein like reference characters refer to corresponding parts in the several views.